Masking frame for making enlargements



July 18, 1961 H. WESTENDORP 2,992,592

MASKING FRAME FOR MAKING ENLARGEMENTS Filed Sept. 24, 195'? .INVENTORS.

HANS WES TENDORP ATTORNEY? United States Patent 2,992,592 MASKING FRAMEFOR MAKING ENLARGEMENTS Hans Westendorp, Opladen, Germany, assignor toAgfa Aktlengesellschaft, Leverkusen, Germany, a corporation of GermanyFiled Sept. 24, 1957, Ser. No. 685,830 Claims priority, applicationGermany Oct. 18, 1956 Claims. (Cl. 88-24) This invention relates to amasking frame for making enlargements, the frame having adjustablymovable enlargement masking strips and an adjustable angular abutmentbearing an angle-shaped masking member which maintains its position, forthe purpose of producing white margins of uniform width on prints madeon any desired paper sizes. The novel feature of the invention is thatthe movable enlargement masking strips are provided with stop bars whichare fixedly, resiliently or ad justably arranged on the strips. The stopbars cause photographic paper laid in the frame to be aligned in thedirection towards the middle of the picture upon moving the maskingstrips and to be shifted towards the angle stop until the fixedenlargement angle frame borne by the fixed angle stop and the movablemasking strips cover the margins of the paper sheet to a constant widthon all sides, so that subsequent trimming of the edges of the picture isunnecessary.

To allow occasional checking of the position of the sheet ofphotographic paper positioned in the masking frame, the stop bars can beprovided with incisions and the masking strips can be provided withclosable apertures at the places above the incisions.

One embodiment of the invention is shown diagrammatically in thedrawing, FIG. 1 being a cross-sectional view of the enlarging maskingframe and FIG. 2 a plan view thereof. In the figures, 1 represents anadjustable precision angle stop, 2 is an enlargement angle mask borne bythe angle stop, 3 is a paper supporting plate and 4 and 5 are movablemasking strips. These masking strips 4 and 5 are provided with stop bars6 which are arranged on the underside of the strips at a distance of 3mm. from the edges of the strips. To allow the abutment of the paper tobe checked, the stop bars 6 are formed with incisions 7, above which aredisposed apertures 8 in the masking strips 4 and 5. These apertures canbe closed against incidence of light during the exposure by means ofspring-loaded flaps 9. Rotatable knobs 10 are provided for moving andadjusting the masking strips 4 and 5. When the adjustable paper anglestop 1 is adjusted to a margin width of 3 mm., it must be spaced exactly3 mm. from the inside edge of the enlargement angle mask 2. If seriesproduction giving such accuracy consistently is not possible, provisionmust be made for subsequent adjustment of the stop member 1.

In the embodiment proposed here, when the masking frame is closed, theangle mask 2 must leave a space of the order of size of a sheet ofphotographic paper of the thickness of card between the base plate 3 andthe mask 2 so that the paper to be exposed can be aligned by the stopsand displaced against the stop angle member 1, to ensure margins ofuniform width on all sides are obtained.

The working procedure is as follows: The paper stop 1 is adjusted to amargin width of 3 mm. The paper to be exposed is pushed against theangle stops in the usual Way and the masking frame is closed.

Using the rotatable knobs 10, the masking strips are moved a fewmillimetres outwards and then inwards.

The stops 6 of the masking strips 4 and 5 abut against 7 the outsideedges of the paper and push this tightly against the angle stop 1, sothat it is simultaneously aligned.

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If the masks 5 are displaced a few millimetres towards the middle of thepicture during the closing operation, for example by resilient bellcrank levers, the movable masks 4 and 5 have only to be adjustedaccording to a scale index for the picture sizes. These masks are thenautomatically pushed towards the edges of the paper and, in acontinuation of this movement, they press the paper in an alignedposition against the angle stops 1, so that margins with a uniform widthon all sides are obtained.

I claim:

1. A masking frame for use in enlarging comprising a paper supportingsurface, first stop means positioned along two adjacent sides of saidsupporting surface adapted for guiding abutment of correspondingadjacent edges of a sheet of photographic paper positioned on saidsurface, an angle mask member disposed along said adjacent sides abovesaid stop means and inwardly extending a predetermined distance past theinward edge of each of said stop means, two adjacent movable maskingstrips disposed along the opposite sides of said supporting surface,said strips being provided with second stop means secured along theirundersides and spaced from the inward edges of said strips apredetermined distance, said angle mask and said strips being positionedwith respect to said supporting surface to allow a sheet of photographicpaper to be slid therebetween in contact with said second stop means,means for moving said strips toward and away from the opposite anglemask, whereby a sheet of paper placed on said surface can be aligned bysaid second stop means and displaced against said first stop meansduring movement of said strips toward the opposite angle mask therebyensuring margins of uniform width on all sides of the paper to beexposed.

2. A masking frame according to claim 1 wherein said second stop meansare provided with incisions defined therein, said masking strips areprovided with apertures defined therein, said apertures being disposeddirectly over said incisions, and means are provided for preventing thepassage of photographic exposure light through said apertures.

3. A masking frame according to claim 1 wherein means are provided foradjusting the predetermined distance said second stop means are spacedfrom the inward edges of said strips and the predetermined distance saidangle mask member extends past the inward edge of said first stop means.

4. The improvement according to claim 2 wherein said means forpreventing the passage of photographic exposure light through saidaperture comprises means for opening and closing said aperture.

5. A masking frame according to claim 1 wherein said second stop meansare provided with stop inward edges spaced from the inward edges of saidstrips a predetermined distance and perpendicular to the plane of saidstrips.

References Cited in the file of this patent UNITED STATES PATENTS1,303,418 Tornsjo May 13, 1919 1,811,123 Glaser June 23, 1931 2,412,507Hunter Dec. 10, 1946 2,418,226 Half Apr. 1, 1947 2,523,669 SchleimerSept. 26, 1950 2,544,883 Isaac et al. Mar. 13, 1951 2,848,923 DiefenbachAug. 26, 1958 FOREIGN PATENTS 31,978 Austria Feb. 25, 1908 565,015Germany Nov. 25, 1932 277,046 Switzerland Nov. 1, 1951

